Granuloma annulare (G.A.) is a dermatosis of unknown cause characterized by papules that are usually present in an annular configuration. It has been reported to follow insect bites, sun exposure and trauma. Some cases appear to be due to hereditary predisposition since the lesions have occurred in identical twins and siblings as well as in more than one generation of patients. It is usually idiopathic.
The most common type of G.A. occurs in children and young adults. Lesions are usually asymptomatic, skin-colored, erythematous or violaceous, well defined, dome shaped papules often arranged in a complete or half circle. Solitary lesions may also be present. Lesions are most commonly seen on the dorsa of the hands and feet, but may appear on the forearms, arms, lower legs, and thighs. The face and scalp are rarely affected.
Other types of G.A. include a variant with larger, deep, dermal or subcutaneous nodules which may occur on the palms, legs, buttocks or scalp. The perforating type of G.A. manifests itself as small papules with central umbilication. These lesions are most frequently reported to occur on the hands and fingers. A more rarely encountered variant of G.A. presents as circinate erythematous lesions usually on the trunk. In older adults, the disseminated form of G.A. is more commonly seen. Hundreds to thousands of individual papules arise anywhere on the skin but with usual marked involvement of the trunk.
Patients with G.A. are generally healthy. Recently, the disseminated form of G.A. has been seen more frequently in patients who are serologically HIV positive. Otherwise, laboratory tests are usually normal. The chief laboratory aid in the diagnosis of G.A. is the skin biopsy. Intradermal foci of granulomatous inflammation are detected which have a central core of incomplete, reversible necrosis (necrobiosis) of collagen surrounded by a wall of palisaded histiocytes intermingled with a few acute inflammatory cells. All variants manifest a similar histopathologic finding but the perforating variant also has central lesion ulceration and communication between the area of necrobiosis and the skin surface.
Granulomas are generally formed by the accumulation of monocytes which, upon proper stimulation, develop into macrophages and may further develop into foreign body multinucleated giant cells. The stimulation causing these developments may come from microorganisms, from locally damaged tissue or from foreign material that is introduced into the body. It is known that cutaneous granulomas can result from the contamination of wounds with particles of soil or glass which contain silicon dioxide (silica).
Although the disease has been reported to spontaneously resolve in two years, lesions tend to be recurrent and usually at the originally involved site. Resolution of recurrent lesions have been reported to occur within another three years.
A wide array of treatment modalities has been employed to hasten the resolution of lesions. These include X-ray therapy, cryotherapy, surgical incision and excision, skin grafting, and intralesional injections of corticosteroids. All such treatment methods are invasive and entail risks of secondary infection, scarring and disfigurement. Orally administered salicylates, antimalarials, dapsone and corticosteroids have also been used. These medications are not without potential and dangerous sequelae. Of all these surgical and medical treatments, only the intralesional injection of corticosteroid is said to be of any benefit. However, these injections are painful and may result in disfiguring cutaneous atrophy of the injected areas.
It would therefore be an improvement in this art to provide a bentonite containing dermal formulation or topical preparation for reversing the granulomatous process of granuloma annulare.
Specifically, it would be an improvement in this art to provide a synergistic, small particle size bentonite-lipophilic agent formulation to safely reverse the granulomatous process of granuloma annulare.